Progress In Electromagnetics Research
ISSN: 1070-4698, E-ISSN: 1559-8985
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By M. Christopoulou, S. Koulouridis, and K. S. Nikita

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ƒA comparative assessment of power absorption in adult and child heads exposed to a small helical antenna at 1710 MHz, is presented, emphasizing the effect of age related parameters. Finite Difference Time Domain simulations are employed to study the interaction between MRI-based head models and a mobile communication terminal equipped with a small helical monopole. A semi-analytical method, based on Green's function theory and the Method of Moments, is used to study the absorption in three-layer spherical head models exposed to a small helical dipole. SAR patterns in child head models derived by non-uniform scaling of adult ones were assessed against SAR patterns computed in child heads derived by uniform downscaling procedures. In both realistic and canonical exposure scenarios, comparable levels of absorbed power (maximum difference: 12%) in adult and child head models were observed. Dependence of SAR values upon separation distance and tissue dielectric properties was quantitatively assessed. In realistic exposure scenarios, the reduction in peak SAR values was 60-80% for a 1 cm increase in distance and up to 16% for a 110% to 90% decrease in dielectric properties values with reference to the nominal value of 100%. These trends were respectively less (55-65%) and more (up to 24%) emphasized in the corresponding canonical exposure scenarios.

M. Christopoulou, S. Koulouridis, and K. S. Nikita, "Parametric study of power absorption patterns induced in adult and child head models by small helical antennas," Progress In Electromagnetics Research, Vol. 94, 49-67, 2009.

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